Duplicating mechanism



Dec. 9, 1969 Original Filed Maw 11, 1964 58l O 584 1 580 580a O A. s. ZERFAHS 3,482,912

DUPLICATING MECHANISM 4 Sheets-Sheet l INVENTOR.

} ARTHUR s. zmmfis Dec. 9, 1969 A. s. ZERFAHS' DUPLICATING MECHANISM 4 Sheets-Sheet 2 Original'Filed Mav 11, 1964 INVENTOR. ARTHUR .5. ZERFAHS BY A7 TORNE) Dec. 9, 1969 A. s. ZERFAHS 3,482,912 DUPLICATING MECHANISM Original Filed Mav 11, 1964 4 Sheets-Sheet;

INVENTOR. ARTHUR S. ZERl-Idl-IS ATTORNEY 4 Sheets-Sheet 4 A. S. ZERFAHS DUPLI CATING MECHANI SM wwm NOw

Dec. 9, 1969 Original Filed Maw 11, 1964 1 wmv INVENTOR ARTHUR SEEM/1'3 ATTORNEY mum United States Patent Int. Cl. G03g /00 US. Cl. 35514 11 Claims ABSTRACT OF THE DISCLOSURE A duplicating machine for automatically making single or multiple copies of the same document and having a selector mechanism which is adapted to be set to a single copy position or to any one of a plurality of multiple copy positions and which is operable, when set at one of the multiple copy positions, to recycle the document through an exposure zone in the machine, to count down one position for each time the document passes through the exposure zone, and to eject the document from its endless path upon its return to its home or single copy position. A gate is actuated to eject the moving document from the endless path. A control for the gate includes a counter and means actuated by the movement of the document along the endless path for producing an electrical pulse each time the document is cycled through the exposure zone. The counter is adapted to be selectively set at least to any one of a plurality of consecutively numbered multiple copy positions and is responsive to said electrical pulses when set to one of said multiple copy positions to count towards a home position at the rate of one position for each pulse. The counter is operative upon reaching said home position to actuate the gate for ejecting said document from the endless path. The pulse producing means includes a document actuated control element. There is means responsive to the document actuation of said control element for applying light to said document as it passes through said exposure zone to effect a light-exposed transfer of the image.

This application is a division of copending application Ser. No. 366,268 filed May 11, 1964 for Automatic Photocopying Apparatus.

The present invention relates to duplicating machines and is especially concerned with duplicating apparatus for automatically making multiple copies of an original document.

A primary object of this invention is to provide a duplicating machine capable of making a single or multiple copies of the same document by alternatively ejecting or recycling the document to be copied a preselected number of times and novel means for automatically actuating the recycle gate.

A further object is to provide a novel mechanism for automatically actuating the recycle gate comprising a means responsive to the movement of the document through the duplicating machine for maintaining said gate in the recycle position for an operator selected number of recycles and then automatically moving said gate to FIGURE 3 is an exploded perspective view as seen from the front, right corner of the printer of FIGURE 1 with the casing removed;

FIGURE 4 is a schematic diagram of the sequencing and control circuit for the printer shown in FIGURE 1;

FIGURE 5 is a perspective view, partially schematic view of the selector dial drive mechanism shown in FIG- URE 2 for conditioning the printer of this invention to automatically make a selected number of copies from a single original document; and

FIGURE 6 is a section taken substantially along lines 66 of FIGURE 2.

Referring now to the drawings, and more particularly to FIGURES 1 and 2, the reference numeral 20 generally designates an electrostatic printing machine comprising a casing 22 removably mounted on a rigid frame 23. Preferably, casing 22 is slidably mounted on suitable upstanding tracks (not shown) so that it may be raised clear of frame 23 and the structure supported thereon.

Arranged within casing 22 is a copy paper supply compartment 24 comprising a shallow sheet metal tray into which photoconductive paper may be loaded in a stack 25. A paper feed mechanism generally indicated at 26 removes sheets of the copy paper from stack 25 in compartment 24 and transports them one at a time through a corona charging unit 27 where a uniform charge of approximately -400 volts is applied to the surface of the copy paper. From charging unit 27, each sheet of copy paper is fed through an imaging station 28 located adjacent the lower end of an imaging projector 29.

The original document to be copied may be manually inserted through a horizontal slot 30 provided in a panel 32 which forms the front wall of casing 22. The document fed through slots 30 is conveyed through an imaging station 33 by means to be described later on. The copy paper is advanced through its imaging station 28 synchronously and in timed relation to the movement of the document through station 33.

Imaging station 33, as shown in FIGURE 2, is located below the forward end of image projector 29. Light is focused on imaging station 33 as by a pair of projection lamps 36 and 37 (FIGURE 3), and an image is reflected from the surface of the original document into an objective lens 40 of projector 29 by a mirror 38. Lens 40 projects the reflected image onto the surface of the sheet of copy paper passing through its imaging station 28. As the image strikes the copy paper, the charge on the paper is reduced by an amount determined by the intensity of the reflected light. The black portions of the original will reflect such a relatively small light intensity as to effect the charge very little, while the light portions of the original will reflect suflicient light intensity as to almost completely release the latent electrostatic charge on the copy paper as is well known in the art.

With continued reference to FIGURE 2, the exposed copy sheet containing the latent charge pattern is developed to provide a visible image as by being passed through a developing tank 44. A liquid developer contained in tank 44 and having charged particles is applied to the latent image bearing surface of the copy paper. These charged particles, which may have a positive polarity, are attracted to negatively charged areas on the copy sheet to a degree determined by the charge at each region on the surface on the copy paper, thereby producing a graphic image. The copy paper feed mechanism then moves the developed copy paper between squeegee rollers 46 and 48 which remove the excess developer from the copy paper and which, if desired, may provide a direct voltage of relatively low magnitude to control the density of the image and/ or the cleanliness of the background of the developed copy paper.

The radiant heat of projection lamps 36 and 37 together with the air warmed by lamps 36 and 37 blown across the copy paper by fans indicated at 50 are effective to remove substantially all of the moisture from the surface of the copy paper. Thereafter, the developed copy paper is discharged by a conveyor 49 onto a tray surface 52 located near the bottom of printer 20 adjacent to panel 32. The sheets of copy paper deposited on surface 52 may be removed by an operator through an opening 1n panel 32.

With reference now to FIGURES 2 and 3, paper feed 26 may comprise a pair of axially aligned, spaced apart feed rollers 60 and 62 fixed on a shaft 64. Rearwardly of shaft 64 is a feed roller 65 which is fixed on a shaft 66. Shaft 66 is rotatably mounted by unshown bearings on frame 23 in parallel spaced apart relationship to shaft 64 and is drivingly connected thereto by suitable belts 68 and 70. Shaft 64 is rotatably mounted by suitable bearings (not shown) on a bracket (not shown) which is rockable about the axis of shaft 66, thereby permitting feed rollers 60 and 62 to be swung upwardly to the dotted line position shown in FIGURE 2 for loading copy paper into compartment 24.

As best shown in FIGURE 3, belt 68 extends around pulleys 72 and 74 which are respectively fixed to corresponding ends of shaft 64 and 66. Similarly, belt 70 9 extends around pulleys 76 and 78 respectively fixed to corresponding ends of shaft 64 and 66 on the opposite side from belt 68. With this construction, feed rollers 60 and 62 are driven by shaft 66 through belts 68 and 70. The weight of shaft 64 together with rollers 60 and 62 and pulleys 72 and 76 is sufficient to provide the necessary friction on the upper surface of the copy paper stack to cause the upper sheet in stack 25 to be advanced when shaft 64 is rotated.

With continued reference to FIGURE 3, feed roller 65 frictionally drives a mating feed roller 100 fixed on a shaft 102 to move the copy paper through the printer. Shaft 102 is rotatably mounted by bearings (not shown) in parallel spaced apart relation vertically below shaft 66. Roller 100 is driven by frictional engagement with roller 65.

As best shown in FIGURE 3, a pair of intermeshing spur gears 104 and 106 are respectively fixed on shaft 66 and a rotatably mounted shaft 107. Spur gear 106 comprises the output member of an electromagnetic clutch 108 which is supported in any suitable manner on frame 23. The input member of clutch 108 comprises a further spur gear 110 about which an endless roller drive chain 112 is trained.

With continued reference to FIGURE 3, chain 112 is trained around and driven by a spur gear 114 which is fixed on an output shaft 117 of an electric drive motor 118. As will presently become apparent as the description proceeds, motor 118 is continuously energized when printer 20 is in operation. As a result, when clutch 108 is energized, a drive train is established for transmitting power from motor 118 through drive chain 112, clutch 108, and spur gears 104 and 106 to rotate shaft 66. By rotating shaft 66, torque is transmitted by belts 6'8 and 70 to rotate shaft 64 with the result that rollers 60 and 62 are revolved in a counterclockwise direction as viewed from FIGURE 2 to advance the top sheet of copy paper in stack 25 toward rollers 65 and 100. As a result of rotating shaft 66, rollers 65 and 100 are revolved in opposite directions for advancing the sheet of copy paper fed from compartment 24 by rollers 60 and 62.

Motor 118 may be mounted by any suitable means (not shown) on frame 23. A fan 119 driven by motor 118 is operative to circulate air through casing 22.

With continued reference to FIGURES 2 and 3, the copy paper advanced by rollers 65 and 100 passes over a rotatably mounted idler roller 120 and between fixed spaced apart deflecting guides 121 and 122 which form a throat 123. The sheet of copy paper advanced by rollers 4 65 and is turned by guides 122 and 121 to descend downwardly. Idler roller assists the copy paper in moving freely through throat 123 to a pair of p1ck-up rollers 124 and 125.

With continued reference to FIGURES 2 and 3, p1ckup rollers 124 and 125 are respectively fixedly mounted on parallel shafts 126 and 128 which are rotatably supported in bearings (not shown) below throat 123. Fixed to one end of the shaft 126 is a spur gear whlch is engaged by drive chain 112 to continuously rotate pickup roller 124. Roller 125 is driven by frictional engagement with roller 124.

The copy paper fed through throat 123 is advanced downwardly by pick-up rollers 124 and 125 for transportation through corona unit 27. Below corona unit 27 is a further pair of parallel, rotatable pick-up rollers 142 and 144. Roller 142 is revolved by drive chain 112 which engages a spur gear 146 fixed on one end of a rotatably mounted shaft 147. Roller 142 is mounted on shaft 147 and frictionally drives roller 144.

With continued reference to FIGURES 2 and 3, the copy paper passing through corona unit 27 is advanced by pick-up rollers 142 and 1-44 to a conveyor 150 which comprises an endless conveyor belt 151 trained around rotatably supported, parallel, spaced apart drive and driven rollers 152 and 154. Belt 151 advances the copy paper through imaging station 28 and maintains the copy paper fiat while the image of the original document is projected on it by image projector 29.

As best shown in FIGURE 3, conveyor 150 is continuously driven by chain 112 which is trained over a spur gear 156. A gear 157 fixed on a shaft 157;: mounting gear 156 constantly meshes with another gear 158 fixed on the end of a rotatably mounted shaft 160. Roller 152 is mounted on shaft 160 and is revolved by drive chain 112 through the drive train formed by gears 156, 157 and 158.

With continued reference to FIGURES 2 and 3, conveyor 150 guides the copy paper to a further pair of pickup rollers 162 and 164 respectively fixed on shafts 165 and 166 below roller 152. To continuously revolve roller 162, a spur gear 167 fixedly mounted on one end of shaft 160 meshes with a rotatably supported idler gear 168 which, in turn, meshes with a gear 170. Gear 170 is fixed on one end of shaft 166 to impart rotation to roller 164. Roller 164 is continuously driven by frictional engagement with roller 162.

Pick-up rollers 162 and 164 feed the copy paper downwardly into developing tank 44. As the copy paper leaves developing tank 44, it is picked up and passed through squeegee rollers 46 and 48 which are rotatably supported on frame 23 by suitable bearings (not shown).

From squeegee rollers 46 and 48, the copy paper is advanced between a further pair of pick-up rollers 174 and 176 which 'are respectively mounted on shafts 178 and 180. Roller 174 is continuously driven by chain 112 which is trained over a spur gear 182 fixed on one end of shaft 178. Roller 176 is driven by frictional engagement with roller 174. A drive train comprising a spur gear 184 fixed on shaft 178 constantly meshes with rotatably mounted idler gear 186 which, in turn, constantly meshes with a gear 188. Gear 188 is fixed on one end of a shaft 190 which mounts squeegee roller 48. Squeegee roller 48 is thus rotated through this drive train and drives roller 46 by frictional engagement therewith.

With continuing reference to FIGURES 2 and 3, the copy paper is advanced by rollers 174 and 176 into a throat 192 defined by conveyor 49 and a fixed metal guide 194. Conveyor 49 comprises a series of endless cords 196 trained around parallel spaced apart rollers 198 and 200 which are respectively fixed on shafts 202 and 204. Conveyor 49 is driven by chain 112 which is trained over a spur gear 206. Gear 206 is fixed to a shaft 208 which is rotatably supported on frame 23 in any suitable manner. A gear 210 fixed on shaft 208 constantly meshes with a gear 212 fixed on shaft 204 so that movement of drive chain 112 imparts rotation to roller 200 to advance cords 196.

Referring now to FIGURES 2 and 3 the original document which is inserted through slot 30 for transportation through imaging station 33 is fed between a pair of pickup roller assemblies 218 and 219 respectively comprising a series of axially spaced apart rollers 220 and 222 extending between parallel, upstanding, spaced apart side panels (not shown) forming a part of frame 23. Rollers 220 and 222 are respectively fixed on parallel shafts 224 and 226 which are mounted by suitable bearings (not shown) on frame 23. Rollers 220 are driven by chain 112 which is trained over a spur gear 228. Gear 28 is fixed on a shaft 230 supported on frame 23 by suitable bearings (not shown). A gear 232 fixed on shaft 230 constantly meshes with a gear 234 which is fixed on one end of shaft 224. Advancement of drive chain 112 thus imparts continuous rotation to rollers 220 through the drive train formed by gears 228, 232, and 234.

Rollers 222 are driven by frictional engagement with rollers 220 so that the document to be copied is advanced by rollers 220 and 222 horizontally toward a further pair of pick-up rollers 236 and 238 which are parallel to rollers 220 and 222 and which are separated from rollers 220 and 222 by a metal guide structure 239 suitably fixed in place on frame 23 and defining a document guide path 240 (FIGURE 2) extending horizontally between rollers 220 and 222 and rollers 236 and 238. Pickup rollers 236 and 238 are respectively fixed on parallel shafts 242 and 244 which are rotatably mounted by suitable bearings (not shown) on frame 23. Roller 238 is continuously rotated by drive chain 112 which is trained over spur gear 246 fixed on one end of shaft 244. Roller 236, which is mounted vertically above roller 238, is rotated by frictional engagement with roller 238.

Pick-up rollers 236 and 238 feed the document to be copied onto a conveyor 248 which comprises an endless belt 250 trained around parallel, spaced apart rollers 252 and 254. Belt 250 supports the document to be copied as it passes through imaging station 33 below the forward upper end of image projector 29.

As best shown in FIGURE 3, roller 252 is fixedly mounted on a shatf 258 which is rotatably supported by suitable bearings (not shown) on frame 23. A spur gear 256 fixed on one end of shaft 258 constantly meshes with a spur gear 260 fixed on shaft 242 with the result that advancement of chain 112 continuously rotates roller 252 to drive belt 250. The rearward movement oft he document on conveyor belt 250 is synchronized with the movement of the copy sheet on conveyor belt 151 by drive chain 112, and the movement of the copy sheet is co-ordinated by use of feeler switches contained in a control circuit to be described later on.

As the document travels off the rear end of belt 250, it passes between a further pair of pick-up rollers 262 and 264 respectively fixed on parallel shafts 266 and 268 whch are rotatably mounted by suitable bearings (not shown) on frame 23. Pick-up roller 262 is driven by a gear 270 fixed on one end of shaft 266 and constantly meshing with a gear 272. Gear 272 is fixed on a shaft 274 which is rotatably mounted on frame 23 and which mounts a spur gear 276. Drive chain 112 is trained over spur gear 276 to continuously revolve roller 262 when motor 118 is energized. Roller 264, which is vertically below roller 262, is driven by frictional engagement with roller 262.

The document conveyed through imaging station 33 is illuminated by projection lamps 36 and 37 which, as shown in FIGURES 2 and 3, may be mounted in a suitable parabolic reflector 277 fixedly supported on frame 23 in such manner as to provide the necessary amount of illumination of the document. The light from projection lamps 36 and 37 is directed through a slot 278 formed in a sheet metal member 279 supported on frame 23 closely adjacent and parallel to the upper run of conveyor belt 250. The image on the document to be copied, as previously explained, is reflected from its surface to mirror 38 which is supported at an upwardly and rearwardly inclined angle adjacent the forward end of casing 22.

With continuing reference to FIGURES 2 and 3, the document fed through imaging station 33 is advanced by roller 262 and 264 into a throat 280 formed by a rear turn around guide 281. Guide 281 comprises forward and rearward arcuate walls 282 and 284 which are fixed on frame 23 in spaced, parallel relationship. As shown, guide 281 deflects the rearwardly moving document into a path traveling toward the front of printer 20.

With continued reference to FIGURES 2 and 3, the copied document is withdrawn from guide 281 by a pair of pick-up roller assemblies 290 and 292. Roller assembly 290 comprises a series of axially aligned, spaced apart feed rollers 294 mounted on a common shaft 296 which is rotatably mounted on frame 23 by suitable bearings (not shown). Roller assembly 292 disposed vertically below roller assembly 290 similarly comprises a series of axially aligned, spaced apart feed rollers 298 fixed on a common shaft 300 which is mounted by suitable bearings (not shown) on frame 23 in parallel relationship with shaft 296.

As best shown in FIGURE 3, rollers 294 are revolved by drive chain 112 which is trained around a spur gear 301 fixed on a rotatably mounted shaft 302. A gear 303 fixed on shaft 302 constantly meshes with a further gear 304 fixedly mounted on one end of shaft 296. Rollers 294 are thus driven by chain 112 through the drive train formed by gears 301, 303, and 304. Rollers 298 are driven by frictional engagement with rollers 294.

In accordance with this invention, the copied document advanced toward the front of printer 20 by roller assemblies 290 and 292 is transferred either into an ejection path 306 or into a recycling path 308 by a gate or flipper 310. Paths 306 and 308 are defined by a removable guide structure 311. The document routed through path 308, is recycled through imaging station 33 for producing multiple copies. The document routed through ejection path 306 is deposited on a tray 312 for removal from printer 20 by the operator. Tray 312 forms a part of guide structure 311.

As best shown in FIGURE 3 flipper 310 may comprise a series of thin, flat sided metal fingers which are fixedly mounted in parallel uniformly axially spaced apart relationship on a common shaft rotatably supported by suitable hearings on frame 23.

Referring now to FIGURES 2 and 4, a main on-oif switch 410 mounted on the front of casing 22 is manually actuated to its on position for initiating operation of printer 20 by completing circuits through motor 118, a pump motor 412, motors 414 and 416 for exhaust fans 50, and a pilot lamp 418. Motor 412 drives a pump 420 (FIGURE 2) which circulates liquid developer or toner solution in tank 44.

Energization of motors 414 and 416 to drive fans 50 effects a flow of air in casing 22 to remove heat produced by the operation of printer 20 and to assist in drying and developing the copy paper after it passes through tank 44 and between squeegee rollers 46 and 48. Energization of motor 118 sets chain 112 in motion to continuously drive rollers 124, 125, 142, 144, 162, 164, 46, 48, 174 and 176 and conveyors 150 and 49 for transporting the copy paper. In addition, chain 112 will also continuously drive rollers 220, 222, 236, 238, 262, 264, 290, 292, and 320 and conveyor 248 for transporting the original document to be copied. Rollers 60, 62, 65 and for removing the sheets of copy paper from stock 25 in compartment 24 will be rotated only when clutch 108 is energized.

With continued reference to FIGURES 2 and 4, switch 410 is connected in series with a pair of interlock switches 422 and 424 mounted on frame 23. Switches 422 and 424 are opened when casing 22 is removed. This prevents operation of printer 20 unless casing 22 is mounted in place on frame 23. With casing 22 mounted in place on frame 23 in the manner shown in FIGURE 1, switches 422 and 424 are closed to permit the circuits to be completed for energizing motors 118, 412, 414, and 416 whenever switch 410 is closed.

Closing of switch 410 also completes a circuit through a normally open switch 426 and a normally closed switch 428 for energizing clutch 108. Clutch 108 is also energizable through a pair of series connected, normally closed switches 430 and 432.

As best shown in FIGURE 2, switches 426 and 430 are mounted on frame 23 and have actuators disposed in the path of the document advanced by rollers 220 and 222 along guide 239. The actuators of switches 426 and 430 are so positioned that switches 426 and 430 will be actuated by the advancing document at the same time. It will be noted that all of the switches shown in FIGURE 4 which are actuated by the traveling document or sheets of copy paper are tripped by the leading edge of the document or copy paper as the case may be and are held in their tripped positions until the trailing edge of the document or copy paper clears the switch actuators.

Switch 428 is also mounted on frame 23 and has an actuator extending into the document feed path 240 between the actuators for switches 426 and 430 and rollers 236 and 238. Switch 432 is mounted on frame 23 and has an actuator extending across the feed path of the copy paper at a point along throat 123 between the ends of guides 121 and 122.

With continued reference to FIGURES 2 and 4, flipper 310 is actuated by a solenoid 434 mounted on frame 23 and having an operating coil 436. One terminal of coil 436 is connected through a conductor 437 to one side of the power source 437a shown in FIGURE 4. The other terminal of coil 436 is connected to a switch blade 440 of a two-position switch 438. Switch blade 440 is engageable with either a contact 442 or a contact 444. Contact 444 is connected through a conductor 446 to switch 410. Con tact 442 is separately connected through a flipper hold switch 448 to conductor 446. Switch 438, as shown in FIGURE 2, is mounted on frame 23 with switch blade 440 extending across the document guide path defined by the rear turn around guide 281 a normally open switch 450 has one terminal connected to conductor 446 and its other terminal connected to contact 444 and also to conductor 437 through a multiple copy dial lamp 452 which is in parallel with operating coil 436.

As best shown in FIGURE 2, solenoid 434 has a plunger 454 connected by a linkage 456 to shaft 318 of flipper 310. A coil spring 458 surrounding plunger 454 biases flipper 310 to its single copy full line position shown in FIGURE 2.

Referring now to FIGURES and 6, switch 450 is actuated by a spring leaf 554 carrying a roller 556 that engages the periphery of a cam 558. Cam 558 is fixed on a rotatable shaft 559 of a selector dial drive comprising a stepper mechanism generally indicated at 562. Shaft 559 is mounted on frame 23 by suitable bearings (not shown) within casing 22. Stepper mechanism 562, as will be explained in detail later on, controls the rotation of shaft 559 and thus the actuation of switch 450 to provide for the production of a selected number of copies from a single original document.

The periphery of cam 558 is smooth and has a uniform radius except for a single longitudinal groove 560. When roller 556 is seated in groove 560 switch 450 is open as shown in FIGURE 4. When cam 558 is rotated so that roller 556 engages any other part of the cam periphery indicated at 563, switch 450 is closed.

With continued reference to FIGURE 5, stepper mechanism 562 is generally of conventional construction and compromises a pivotally mounted spring biased pawl 566 which is engageable with a ratchet wheel 568 fixed on shaft 559. Pawl 566 is attracted by energizing a stepper coil 572.

As shown in FIGURE 4, coil 572 is in parallel with coil 436. One terminal of coil 572 is connected to conductor 446 through a normally open switch 574, a normally closed switch 576, and a normally open switch 578. The other terminal of coil 572 is connected to conductor 437. As a result, switches 574, 576, and 578 in addition to switches 410, 422, and 424 all must be closed before coil 572 can be energized to attract pawl 566. As coil 572 is intermittently pulsed in a manner to be described shortly, pawl 566 engages ratchet Wheel 568 to rotate shaft 559 and cam 558.

As best shown in FIGURE 6, shaft 559 is coaxially formed with a smooth, blind bore 579 which slidably receives a dial shaft 580. A member 580a fixed on shaft 580 non-rotatably mounts a selector dial 581 within casing 22. Shaft 580 projects forwardly beyond panel 32 and non-rotatably mounts a suitable knob 582 to permit an operator to manually set the dial drive mechanism for making a selected number of copies from an original document. For this purpose, dial 581 is provided with circumferentially spaced indicia which are displayed' through a window 582a in panel 32.

With continued reference to FIGURE 6, a cylindrical pin 583 is received in a transverse through bore in shaft 580 and slidably projects at one end into a longitudinal, forwardly opening slot 584 formed in shaft 559 to nonrotatably lock shafts 559 and 580 together. By turning dial 581, shaft 559 is rotated to a position for conditioning printer 20 to automatically produce a selected number of copies as will be explained in greater detail later on. When it is desired to remove casing 22, shaft 580 is first axially withdrawn from bore 579. Dial 581 is slidably mounted along member 580a which is removed with shaft 580. As shown, dial 581 is provided with a hub portion extending through the opening in panel 32 and having an annular recess 584a. When shaft 580 and member 580a are fully removed, dial 581 drops into a position wherein recess 584a receives a portion of panel 32, thereby supporting dial 581 on panel 32 when casing 22 is removed.

As best shown in FIGURE 5, switch 578 is provided with an actuator which is operated by leaf 554 simultaneously with the operation of switch 450. Switch 574 is mounted on frame 23 and, as shown in FIGURE 2, has an actuator extending into the document feed path 240. Switch 574 is tripped by a document advancing towards rollers 236 and 238 simultaneously with the actuation of switches 426 and 430.

To produce only one copy of an original document, dial 581 is turned to a single copy position where roller 556 seats in groove 560. In this position, switches 450 and 578 are opened to respectively interrupt the circuits for energizing solenoid 434 and coil 572. As a result, flipper 310 is biased into its full line, single copy position shown in FIGURE 2, and stepper mechanism 562 is inoperative to rotate cam 558 for actuating switches 450 and 578.

With motor 118 energized as a result of closing switch 410 and with dial 581 set to its single copy position, clutch 108 will be energized through switches 430 and 432. Rollers 60 and 62 engaging the top sheet of copy paper in stack 25 will be rotated in a counterclockwise direction as viewed from FIGURE 2 to feed the top sheet of copy paper through a slot in the rare end of compartment 2.4. The sheet of copy paper advanced by rollers 60 and 62 is fed between pick-up rollers 65 and which advances the copy paper between guides 120 and 121 to trip switch 432 to its open position.

By opening switch 432 clutch 108 is immediately deenergized to interrupt the drive to rollers 60, 62, 65 and 100. By stopping rotation of rollers 65 and 100, the advancement of the sheet of copy is stopped at a ready 9 position with its leading edge engaging the actuator of switch 432, thereby holding switch 432 open. It will be noted that the leading edge of the copy paper at this ready position is spaced from rollers 124 and 125 which are continuously rotated as long as motor 118 is energized.

With continued reference to FIGURES 2 and 4, the leading edge of the sheet of copy paper also engages an actuator of a normally open switch 586 simultaneously with the engagement of the actuator of switch 432. Switch 586 is closed by the advancement of the copy paper to its ready position to complete a circuit for energizing a feed lamp 588 through a pair of normally closed switches 590 and 592. Switches 586, 590 and 592 are connected in series with feed lamp 588 across conductors 437 and 446. Thus, when a sheet of copy paper is advanced to its ready position, feed lamp 588 will be illuminated provided that switches 590 are closed.

Switch 590 is mounted in frame 23 and, as shown in FIGURE 2, has an actuator extending into the document feed path 240. By advancing a document to be copied into printer 20, switch 590 is opened simultaneously with the actuation of switches 42.6, 430, and 574. Switch 592 is held closed by leaf 593 and cam 595 when roller 556 is seated in groove 560 of cam 558. Switch 92 remains latched in its closed position even though dial 581 is turned to some multiple copy position by latch 597. When stepper solenoid 572 is energized it raises latch 597 and switch 592 opens and remains open until cam 558 is rotated to its single copy position where cam 595 engages leaf 593 to close switch 592.

Considering the operation of printer 20 for producing a single copy of an original document, cam 55 8, as previously mentioned, is turned to its single copy position where roller 556 seats in groove 560 to open switches 450 and 578 and to close and latch switch 592. When switch 410 is closed, energizing motor 118, clutch 108 is energized through switches 430 and 432 to transmit power for driving rollers 60, 62, 65, and 100. By rotating rollers 60 and 62, the top sheet of copy paper in stack 25 is advanced between rollers 65 and 100 which feed the copy paper through throat 123 to its ready position where its leading edge engages the actuators of switches 432 and 586 to open switch 432 and close switch 586. Opening of switch 432 de-energized clutch 108 to stop the advancement of the copy paper short of rollers 124 and 125 which are continuously rotating as previously explained. Closing of switch 586 completes a circuit through switches 590 and 592 to energize feed lamp 588, signalling the operator to manually feed in the original document to be copied into the printer.

The original document inserted through slot 30 is advanced along guide path 240 by rollers 220 and 222 which are rotating continuously. The leading edge of the document after passing between rollers 220 and 222 simultaneously engages. the actuators of switches 426, 430, 574, and 590 to close switches 426 and 574 and to open switches 430 and 590. Opening of switch 590 interrupts the circuit for feed lamp 588 to signal the operator of the printer. Closing of switch 574 will not complete a circuit for energizing stepper coil 572 since switch 57 8 is held open by cam 558.

By closing switch 426, another circuit through switch 428 is momentarily completed to re-energize clutch 108. As a result, a drive connection is established at the moment the leading edge of the original document actuates switch 426 to again rotate rollers 65 and 100 and advance the sheet of copy paper which had been previously advanced to its ready position in throat 123. This control of the operation of clutch 108 by the advancement of the original document towards imaging station 33 thus establishes a timed relationship between the movement of the copy paper and the document to be copied to assure that the copy paper and the document pass through their respective imaging stations 28 and 33 at the same time.

After switch 426 is closed by advancement of the document to be copied, clutch 108 remains energized by the circuit traced through switches 426 and 428 until the leading edge of the document has advanced sufficiently far along guide 239 to trip switch 428 to its open position. Opening of switch 429 interrupts the energizing circuit for clutch 108, and since switch 432 is held open by the sheet of copy paper advancing from its ready position, clutch 108 will remain de-energized until the trailing edge of the copy paper clears the actuator of switch 432 and the trailing edge of the original document clears the actuator of switch 430. Thus, clutch 108 remains re-energized to advance the sheet of copy paper from its ready position in throat 123 for the period of time that the leading edge of the document to be copied moves from the actuator of switch 426 to the actuator of switch 428.

The distance along the copy paper guide path between the actuator of switch 432 and rollers 124 and is somewhat less than the distance along the document guide path between the actuators of switches 426 and 428. Since the copy paper and the document to be copied are both advanced by motor 118 at essentially the same speed, then the sheet of copy paper will be advanced sufficiently far to be picked up by rollers 124 and 125 when clutch 108 is momentarily energized through the circuit completed by closing switches 426 and 428. As previously explained, rollers 124 and 125 are continuously rotated as long as motor 118 is energized to feed the copy paper toward corona unit 27.

At the same time that the leading edge of the document to be copied engages the actuators of switches 426, 430, 574, and 590, it also engages an actuator of a normally open switch 596 which, as shown in FIGURE 4, is connected in series with a primary winding 59 8 of a high voltage transformer 600. Transformer 600 is provided with a secondary winding 602 which is preferably connected to corona unit 27. When the actuator of switch 596 is tripped by the advancing document, switch 596 closes to complete a circuit through Winding 598 to energize corona unit 27 at the same time that clutch 108 is re-energized to start the advancement of the first sheet of copy paper from the ready position in throat 123 towards rollers 124 and 125. Rollers 124 and 125 feed the copy paper through corona unit 27 which now has been activated to apply a uniform charge to the copy paper surface as previously described. Rollers 142 and 144, which are also continuously rotated when motor 118 is energized, pick up the charged copy paper emerging from corona unit 27 and advance the copy paper towards imaging station 28.

Referring to FIGURES 2 and 4, the leading edge of the advancing document to be copied trips an actuator to close a further normally open switch 604 at the same time that it trips switch 596. Actuation of switch 604 to its closed position closes a circuit to another normally open switch 606 which is tripped to its closed position by the leading edge of the advancing document at the same time that switch 428 is opened. Switches 428 and 606 are tripped by the advancing document considerably before the trailing edge of the document clears the actuators of switches 426, 430, 574, 590, 596, and 604 with the result that switches 426, 430, 574, 590, 596, and 604 are held in their tripped positions when the document trips switches 428 and 606.

By closing switches 604 and 606 a circuit is completed to energize a winding 608 of a relay 610 in an energizing network for projection lamps 36 and 37. Energization of relay 610 closes two sets of normally open relay contacts 612 and 614 and opens switch 57 6. Contacts 612 and 614 are respectively connected in series with projection lamps 36 and 37 are illuminated by advancement of the document to be copied to the position along guide path 240 where it trips switch 606 after tripping switch 604.

The function of switch 576 will be explained later on in connection with the production of multiple copies.

The document to be copied is advanced by rollers 220 and 222 to rollers 236 and 238 which feed the document through imaging station 33. At the same time, the sheet of copy paper advanced through corona unit 27 is picked up by rollers 142 and 144 which feed the copy paper through imaging station 28. The copy paper and the document to be copied are advanced through their respective imaging stations at the same speed.

As the original document passes through its imaging station 33, it is struck by the light emitted from projection lamps 36 and 37, and the image of the document is reflected by mirror 38 into the image projector 29 through lens 40. The image passing through imaging projector 29, emerges through a glass slate 618 (FIGURE 2) and strikes the negatively charged surface of the copy paper passing through imaging station 28. The uniform negative charge on the copy paper is reduced in proportion to the intensity of the light striking the copy paper surface. Since little light will be reflected from the black areas of the original, the charge on areas of the copy paper against which the light reflected from such areas strikes will be reduced very slightly. On the other hand, the charge on areas of the copy paper struck by the light reflected from white areas of the original, such as the white background of a letter, will almost be entirely dissipated since the most intensive light will be reflected from those areas. As the original and the copy paper continue through their respective imaging stations, the image on the original is reproduced in latent form on the copy paper through dissipation of the charge on its surface in the manner described above.

As the copy paper emerges from imaging station 28 as shown in FIGURE 2, it simultaneously trips two normally open switches 620 and 622 before entering tank 44. By closing switch 620, a further circuit, as shown in FIGURE 4, is provided in parallel with the circuit through switches 604 and 606 for maintaining relay 610 energized. Shortly after switch 620 is tripped, the trailing edge of the original document clears the actuators of switches 426, 430, 574, 590, 596, and 604 where the original document and the sheet of copy paper are about the same length. As a result, switches 426, 574, 596, and 604 will open, and switches 430 and 590 will close. Although switch 604 opens at this time, projection lamps 36 and 37 remain illuminated as a result of the relay energizing circuit completed by closing switch 620.

If the sheet of copy paper and the document are the same length, the trailing edge of the copy paper will clear the actuators of switches 432 and 586 at the same time that the trailing edge of the document clears the actuators of switches 426, 430, 574, 590, 596, and 604 with the result that switches 432 and 586 will respectively open and close at the same time that switches 426, 574, 596, and 604 open. Closing of switches 430 and 432 again completes a circuit for energizing clutch 108 to drive rollers 60 and 62 for advancing the next sheet of copy paper in stack 25 to rollers 65 and 100. Rollers 65 and 100, as previously described, advance the new sheet of unprocessed copy paper through throat 123 to the ready position where the leading edge of the copy paper trips switch 432 to de-energize clutch 108. With dial 581 set at its single copy position, an original document must again be inserted manually into the printer to cause further advancement of this sheet of unprocessed copy paper from its ready position.

After the trailing edge of the original document clears the actuator of switch 596, corona unit 27 remains energized through switch 622 and a normally open switch '624. Switch 624 is connected in series with switch 622 and winding 598 and has an actuator which is positioned in document feed path 240 to be tripped to its closed position simultaneously with the actuation of switches 428 and 606. Corona unit 27 will remain energized as a result of the closing of switch 622 by the copy paper and the closing of switch 624 by the original document.

When the trailing edge of the original document clears the actuators for switches 428, 606, and 624, switch 624- will open to de-energize corona unit 27. Although switch 606 opens at this stage of the operation, relay 610 and, consequently, projection lamps 36 and 37 remain energized through switch 620.

As the copy paper which was advanced through corona unit 27 and imaging station 28 passes through tank 44, its trailing edge clears the actuator for switch 620, permitting this switch to open with the result that projection lamps 36 and 37 will turn otf. The processed copy paper is advanced from tank 44 to surface 52 where it may be removed from the printer as previously explained. The original document, in the meantime, is advanced through the rear turn-around guide 281. As the document emerges from guide 281, it is picked up by rollers 290 and 292 and fed toward front panel 32. With flipper 310 in its raised, full line position shown in FIGURE 2, the document advanced by rollers 290 and 292 is guided under flipper 310 and is deposited in tray 312 for removal by the operator.

To automatically make more than one copy of an original document, dial 581 is manually set to the number of copies desired. This revolves ratchet wheel 568 by a number of notches corresponding to the number of copies to which dial 581 is set. By turning dial 581 away from its single copy position, cam 558 is also rotated to displace roller 556 from groove 560, causing it to engage periphery 563. As a result switches 450 and 578 will close.

By closing switch 450, solenoid 434 is energized to swing flipper 310 downwardly to its document recycling position shown in dot-dash lines in FIGURE 2. Also, switch 448 is closed by energizing solenoid 434 for a purpose to be explained shortly. By closing switch 578, a circuit for energizing stepper coil 572 will be established when switch 574 is closed, provided that switch 576 is also closed.

When switch 410 is now closed, motors 118, 412, 414, and 416 and clutch 108 are energized in the manner previously explained. As a result, the top sheet of copy paper is advanced from stack 25 to its ready position in throat 123 where the leading edge of the sheet trips switches 432 and 586 to deenergize clutch 108 and energize feed lamp 588 as previously described. The operator now feeds the document to be copied through slot 30 where it is picked up by rollers 220 and 222 and advanced along guide path 240. As the document is fed towards imaging station 33, the leading edge of the document will trip switch 574 to its closed position simultaneously with the actuation of switches 426, 430, 590, 596 and 604 as previously described. By closing switch 574 a circuit is completed through switch 576 and 578 to energize stepper coil 572. Switch 576 will be closed since, at this stage of the operation, relay 610 is de-energized.

Advancement of the document to be copied a short distance along guide path 240 trips switch 606 to its closed position in addition to actuating of switches 428 and 624. By closing switch 606, as previously explained, a circuit is completed through switch 604, which is being held closed by the document in guide path 240, to ener gize relay 610, thereby opening switch 576 to interrupt the energizing circuit for stepper coil 572. Thus by the closing of switch 574 followed shortly by the opening of switch 576, stepper coil 572 is pulsed to momentarily attract pawl 566, causing it to revolve ratchet wheel 568 by one notch towards the notch that corresponds to the single copy position where roller 556 seats in groove 560.

Assuming that dial 581 was originally set to make three copies of the original document, the first pulse of stepper coil 572 resulting from the sequential actuation of switches 574 and 576 moves cam 558 to a position where 13 groove 560 is removed from roller 556 by a distance corresponding to two notches on ratch wheel 568. As a result, switches 450 and 578 are still held in their closed positions.

The first pulse of stepper solenoid 572 unlatches the actuating leaf of switch 592, permitting switch 592 to open with the result that the energizingcircuit for feed lamp 588 is interrupted. Lamp 588 will not be illuminated again until cam 558 is rotated to its single copy position where roller 556 seats in groove 560 to close and relatch switch 592 and until another sheet of copy paper is fed from compartment 24 to close switch 586.

As the original document is advanced along guide path 240, clutch 108 is re-energized momentarily in the manner previously explained to start the advancement of the copy paper at the ready position in throat 123. In addition, projection lamps 36 and 37 and corona unit 27 are energized in the manner described in the operation of printer for making a single copy. The original document and the first sheet of copy paper then pass through their respective imaging stations 28 and 33, and the image of the original is printed on the copy paper which then is conveyed through tank 44 to tray surface 52.

As the original document clears the actuator of switch 430 and the first sheet of copy paper clears the actuator of switch 432, switches 430 and 432 close to re-energize clutch 108 to revolve rollers 60, 62, 65, and 100 for advancing the next sheet of copy paper in stack 25 to the ready position in throat 123 in the same manner as previously described. The original document advancing through imaging station 33 is fed through the rear turn around guide 281 where its leading endge trips switch 438 to shift switch blade 440 into engagement with contact 442. The solenoid energizing circuit for holding flipper 310 in its downwardly swung, recycling position is now established through switch 448. This flipper solenoid energizing circuit arrangement assures continuity of power to keep flipper solenoid 434 energized as the document passes over flipper 310 even if dial 581 is set back at this time to its single copy position.

As a result of retaining flipper 310 in its recycling position, the document emerging from the rear turn around guide 281 is routed through path 308 and into throat 321 where the front turn around guide 322 deflects the document, as previously described, into the nip between rollers 220 and 222. Rollers 220 and 222 recycle the document through guide path 240 where switches 426, 430, 574, 596, and 604 are first tripped, followed by the actuation of switches 428, 606, and 624 in the same manner as hereinbefore described.

The sequential actuation of switches 574 and 576 again pulses stepper coil 572 to rotate cam 558 by a distance corresponding to one notch on ratch wheel 568. In this position roller 556 still engages the cam periphery and is removed from the groove 560 by a distance now corresponding to only one notch on ratch wheel 568 with the result that switches 450 and 578 are still held in their closed positions.

Recycled advancement of the original document along path 240 and through station 33 operates clutch 108 to advance the second sheet of copy through corona unit 27 and imaging station 28 with the result that a second copy is produced. Also, the third sheet of copy paper in stack 25 is withdrawn from compartment 24 and advanced to its ready position in throat 123. Operation of the various control switches resulting from the recycling of the original document and the advancement of the second sheet of copy paper is the same as previously explained.

Since flipper 310 is still held in its downwardly swung, recycling position, the original document, which at this stage, has passed through the imaging station twice will again be routed through path 308 and into throat 321 where guide 322 deflects it into rollers 220 and 222.

As the document is now advanced for the third time along guide path 240, it will cause the sequential actuation of switches 574 and 576 to pulse stepper coil 572 for the third time. The third pulse of coil 572 now returns cam 558 to its single copy position where roller 556 seats in groove 560. As a result, switches 450 and 578 will open to interrupt the energizing circuits for stepper coil 572 and for flipper solenoid 434. Flipper 310 is then released to swing upwardly to its single copy position.

The document and the third sheet of copy paper will now pass through their respective imaging stations 33 and 28 to produce the third and final print. When the document now emerges from the rear turn around guide 281, flipper 310 being in its upwardly swung, single copy position, routes the document into ejection path 306, depositing the document on tray 312 for removal by the operator. Actuation of switch 438 by the document as it is recycled in making the third print will not be effective to energize flipper solenoid 434 since switch 448 was opened as a result of de-energizing solenoid 434 when the document was advanced for the third time along guide path 240.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

I claim:

1. In a duplicating machine having a duplicating station, means for cylically advancing a document to be copied along an endless path passing through an exposure zone in said station, means for feeding copy paper along a second path distinct from said endless path through said duplicating station in timed relation with the movement of said document therethrough to enable the transfer of an image from said document to said copy paper as the document and copy paper pass through said station, gate means actuatable to eject the moving document from said endless path, and means for controlling actuation of said gate means and including counting means and means actuated by movement of said document along said endless path for producing an electrical pulse each time said document is cycled through said exposure zone, said counting means being adapted to be selectively set at least to any one of a plurality of consecutively numbered multiple copy positions and being responsive to said electrical pulses when set to one of said multiple copy positions to count towards a home position at the rate of one position for each pulse,

said counting means being operative upon reaching said home position to actuate said gate means for ejecting said document from said endless path, said pulse producing means including a document actuated control element comprising a first document actuate-d switch, said pulse producing means further comprises a second switch actuated by said traveling document before it actuates said first switch to initiate said pulse, said first switch being adapted upon actuation for terminating said pulse, and means responsive to the document actua ion of said control element for applying light to said document as it passes through said exposure zone to effect a light-exposure transfer of said image.

2. In the duplicating station defined in claim 1, said first document actuated switch being adapted upon actuation for completing a first electrical circuit, and said second switch being adapted upon actuation to complete a second circuit that initiates said pulse, said pulse producing means further comprising a third switch contained in said second circuit, and means responding to the completion of said first circuit for actuating said third switch to a position where it interrupts said second circuit for terminating said pulse.

3. The duplicating machine defined in claim 2 wherein said means for actuating said third switch comprises an electrical component disposed in said first circuit for energization by completion of said first circuit and wherein said light applying means comprises means operated by energizing said component.

4. The duplicating machine defined in claim 3 wherein said electrical component comprises a relay winding energized by completion of said first circuit to actuate said third switch.

5. The duplicating machine defined in claim 3 wherein said light applying means further comprises a lamp contained in a third circuit and wherein said means operated by energization of said component comprises contacts for completing said third circuit to energize said lamp.

6. The duplicating machine defined in claim 2 comprising a fourth switch contained in said second circuit and being actuated by said counting means when at its home position for interrupting said second circuit to prevent said pulses from being produced as long as said counting means is in said home position.

7. The duplicating machine defined in claim 6 wherein said means controlling actuation of said gate means comprises switch means actuated by said counting means when at said home position, and means responsive to actuation of said switch means for actuating said gate means to a position for ejecting a document from said endless path, said exposure zone being disposed along said path at a position that is between said gate means and the region of said path where said document is adapted to be selectively inserted into said path, whereby the positioning of said counting means in said home position prevents said document from being cycled more than one time through said exposure zone to provide for the production of a single copy.

8. The duplicating machine defined in claim 7 wherein said counting means is operative in response to said pulses to count down from any of said multiple copy positions to said home position.

9. The duplicating machine defined in claim 1 wherein said pulse producing means is disposed at a region of said endless path to be actuated by the travelling document each time before the document passes through said exposure zone.

10. The duplicating machine defined in claim 1 comprising an indicator lamp, a circuit providing for the energization of said lamp before the insertion of a document into said endless path, and means responsive to the first pulse produced by said document actuated means at least when said counting means is in one of its multiple copy positions to interrupt said circuit for extinguishing said lamp and to maintain said circuit interruption until said counting means counts to its home position.

11. In a duplicating machine, a duplicating station, means for cyclically routing a document to be copied along an endless path passing through an exposure zone in said duplicating station, means for feeding copy paper through said duplicating station in timed relation with the movement of said document therethrough to enable the transfer of an image from said document to said copy paper as the document and copy paper pass through said station, gate means actuatable to eject the moving document from said endless path, means actuated by movement of said document along said endless path for producing an electrical pulse each time said document is cycled through said exposure zone, counting means adapted to be selectively set at least to any one of a plurality of consecutively numbered, multiple copy positions, said counting means when set to one of said positions being responsive to the electrical pulses produced by the document movement to count towards a home position at the rate of one position for each pulse and being operative upon reaching said home position to actuate said gate means for ejecting said document from said endless path, an indicator lamp, means responsive to the advancement of the copy paper to a predetermined position ahead of said duplicating station for completing a circuit to energize said lamp to provide a visual indication to an operator for inserting a document to be copied into said endless path, and means responsive to the first pulse produced by said document actuated means upon insertion of the document into said path for interrupting said lamp energizing circuit to extinguish said lamp when said counting means is in one of its multiple copy positions at the time of document insertion into said path, said last-mentioned means being operative to maintain said circuit interruption until said counting means advances to said home position.

References Cited UNITED STATES PATENTS 2,657,613 11/1953 Maker -75 X 2,927,210 1/1960 OMara 95-75 X 3,136,237 6/ 1964 Moon 9577.5 3,181,420 5/1965 Rautbord 95-77.5 X 3,215,056 11/1965 Campbell 95--77.5 3,272,100 9/1966 Teutsch 951.7 3,088,386 5/1963 Sugarman 95-l.7 3,091,169 5/196-3 Taini 95--77.5 3,136,237 6/1964 Moon 95-77.5

JOHN M. HORAN, Primary Examiner 

